As society becomes increasingly reliant upon technology, mechanical and electromechanical systems, such as aircraft, automobiles, weapons systems and power systems, are called upon to perform an ever increasing number of functions. One downside to this is that, in some situations, a failure of a single threaded component in the system may cause a catastrophic failure of the entire system possibly resulting in the loss of millions of dollars and hundreds of lives. In an attempt to reduce the probability of a catastrophic systems failure, critical and some non-critical systems are required to satisfy predetermine operating tolerances before they may be used. As such, key threaded components within these systems, i.e. threaded components whose failure may cause a catastrophic system failure such as internally threaded rings, nuts and/or plain and threaded ring gages, must also satisfy operating tolerances. If a threaded component fails to satisfy these required design tolerances and/or performance specifications, a degradation of system performance and/or a total system failure may occur resulting in damage to the system and/or injury/loss of life to an operator and/or bystander.
Current systems used for inspecting physical characteristics of an internally threaded component employ an attribute inspection approach that measures the characteristics of the threaded component via a contact measurement technique. This technique typically uses GO and/or NO GO threaded work plugs that are calibrated to specifications. The internal thread size measurement are conducted via GO and/or NO GO working plugs and gages. Unfortunately, this technique only measures the functional size and does not protect and ensure the dimensional integrity of product design limits and because this approach is attribute gagging and is dependent upon human interaction, this technique has the disadvantage of being time consuming, subjectively inaccurate and unreliably repeatable for tight operating tolerances over multiple measurements. Accordingly, threaded components having dimensionally non-conforming characteristics are allowed to pass inspections. Moreover, because these systems use contact measuring techniques, there is a considerable wear factor on the measuring instruments, requiring the GO, NO GO, threaded working plugs and variable internal gauging elements to be inspected and replaced often.